电容型电气设备介质损耗角的在线监测

在线监测容性设备的介质损耗是判断其绝缘状况的有效手段。作者通过与容性设备末屏串联分压电容的方法提取工频电压信号，采用绝对测量和过零比较法相结合的新方法测量介质损耗角；对影响测量精度的相关问题进行了分析，并提出了解决办法；引入了横向比较法和趋势分析法等绝缘诊断策略。试验结果证明所提出的方法能满足测量的可信度、准确度和稳定度要求，可实现介质损耗角的在线监测。

On-Line Monitoring of Dielectric Loss of Capacitive Apparatus

To assess the insulation condition of capacitive apparatus, on-line monitoring of dielectric loss angle is an effective measure. By means of connecting divider capacitor in series with the outmost shielding layer of the bushing for capacitive apparatus, the fundamental frequency voltage signal is extracted, then the dielectric loss angle is measured by a new approach that combines absolute measurement method with zero crossing comparison method. The related factors influencing measurement accuracy are analyzed and corresponding solutions are proposed. In addition, the insulation diagnosis strategy, such as relative comparison and trend analysis, are adopted. Testing results show that the proposed method can meet the requirements of measurement with regard to confidence, accuracy and stability, so it can be used in on-line monitoring of dielectric loss angle.